1. Field of the Invention
The present invention relates to a data processing system, and more particularly to a data read device for optically reading symbols, such as bar codes on articles.
2. Description of the Related Art
A settlement system as shown in FIG. 1 is known, and includes a scanner SN for optically reading a bar code on an article, and an electronic cash register RG for processing bar code data supplied from the scanner SN. The register RG is used as a POS (point of sales), for example.
For the purpose of payment, a customer places a basket 1 containing articles on a check stand 2A, a cashier removes the articles one by one from the basket 1, and reads the bar codes on the articles by passing them across the scanner SN. Thereafter, the cashier places the scanned articles in a basket 4 situated on another check table 2B. Specifically, the scanner SN reads the bar code on an article when the article is moved across a window 3 in the direction of arrow A, and supplies the bar code data corresponding to the read bar code to the cash register RG, which produces sales data in accordance with items of the bar code data.
Consider the case where a bar code is partly illegible due to blurring, for example, and the scanner SN fails to read all of the bar code. In this case, an attempt is made to read the bar code again, and to this end, the cashier moves the article in the direction of arrow B and returns it to the basket 1 side, and again passes it in front of the window 3, in the direction of arrow A. In the conventional settlement system, there is a possibility that the bar code on an article read twice or more during the movement of the article. If items of identical bar code data are supplied from the scanner SN, the cash register RG processes these bar code data and produce erroneous sales data as a result of the processing. To correct this sales data, intricate procedures are required.